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ExoMars
Paolo
post Jun 14 2011, 07:55 PM
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exactly, and to show that all the million euros invested in the program have not been completely wasted


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I'm one of the most durable and fervent advocates of space exploration, but my take is that we could do it robotically at far less cost and far greater quantity and quality of results.

James Van Allen
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djellison
post Jun 14 2011, 10:03 PM
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Respecting the admin teams wishes to not revert to the back and forth with vjkane....

Mars-Next? Really?

It's mentioned on an ESA website from 3.5 years ago, and nowhere else.
http://www.esa.int/esaSC/SEMJA563R8F_index_0.html

That means it predates the 2016 EDL test being announced - thus the EDL test can not be considered a precursor to Mars-Next

Moreover - the possible post-2018 mission is mentioned here - http://mepag.jpl.nasa.gov/meeting/jul-09/0...ag_Coradini.pdf - in the context of a 200kg 2016 test of an appropriate net-lander sized vehicle... NOT a 600kg Phoenix sized lander that we now seem to be heading towards.

Mars-Next reappears at LPSC in 2008
http://www.lpi.usra.edu/meetings/lpsc2008/pdf/1656.pdf

The 2009 LPSC paper is identical to the 2008 one in almost every way. Not a great sign of a project moving forwards. 'We need to submit an LPSC paper' 'Copy and paste last years'. Marching forwards, clearly.

Those documents wording describes this as a project to fill the gap between ExoMars and MSR....but it seems increasingly likely that ExoMars (2018) will become the first leg of a three-phase MSR project - so no such gap exists anymore.

Do the requirements of the Mars-Next landers match the abilities of the 2016 test lander? If it does, why is it just an EDL test. If you're about to build 4 of something.... then surely this test should be an end to end test of EDL AND the long life surface phase requirements.

If we assume that yes, Mars-Next IS a long life derivation of the 2016 test lander, then could an orbiter realistically carry four landers of this size? The 2016 test is a 600kg vehicle (neither small enough for realistic netlander, nor big enough for the sorts of payloads scientists want to send) 4 of those is more than twice the dry mass of MRO. It's more than the wet mass of MRO...just the carried payload. This would result in a spacecraft getting on for Cassini/Galileo/Phobos sized. Building and testing that much hardware would cost a FORTUNE. Can ESA realistically afford 4 landers of that size? It's easily an MER + MRO budget project. With the 2016 Orbiter and Lander, and a 2018 rover to pay for, there can not possibly be money for such a project.

Calling the 2016 lander a test-bed for an unfunded (and frankly unfundable) project that almost certainly wont take the 2016 lander design on is just a little bit of a stretch. At this point, the 2016 EDL test looks like an inappropriate test for an unfunded project who's Mars program window just vanished.

That 200kg EDL test proposed back in 2009 sounds awesome and could very well constitute the beginning of a Mars-Next style project in the future - the very Netlander project I've been bashing on and on about for years as a logical goal for ESA. Unfortunately, far from being a test-bed, it would appear to me that the new large 600kg 2016 EDL test actually kills any chance of Mars-Next happening.

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spdf
post Jun 15 2011, 12:36 PM
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Well I could find more documents about Mars-Next. This one is from November 2010.

http://emits.esa.int/emits-doc/ESTEC/ESAIP...xp2009-2014.pdf

ESA thinks about an Ariane 5 launch. Mass at launch will be 3363 kg. 3-6 landers at a mass of 170 kg. Okay point taken.
It seems like they think that entry is the most critical point for them, not long life surface phase requirements. That seems to be why the main target of the test is the entry phase. No judgement from me about this. (No time to read the whole document now)

Concerning the budget, JAXA is also thinking about a network mission called MELOS. There seems to be talk about going somehow together. I can post some documents about this later, if you want.
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djellison
post Jun 15 2011, 02:01 PM
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QUOTE (spdf @ Jun 15 2011, 04:36 AM) *
3-6 landers at a mass of 170 kg.


Like I said - the 600kg test lander actually kills off an EDL test for a vehicle of this size.

And that's not really a document about Mars-Next (infact, that phrase doesn't appear in the entire 100 pages of it) - it's the technology roadmap for robotic exploration of the entire agency. Yes, it talks about a presumed networked lander - it simply cites 2011 funding for 4 different technological requirements - Aerogel, UHF/Xband comms, an orbiter re-entry breakup analysis tool and small lander airbags.. total funding is 3.6M Euros. It cites other tech research projects that would stretch into 2014 as a precursor to any possible network lander projects. It doesn't attest as to the likelihood of such a mission happening.
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vjkane
post Jun 15 2011, 03:34 PM
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When comparing masses, be sure to know what elements are included. Depending on the context, the mass can include:

Landed system only
Landed system + descent system
Landed system + descent system + entry system
Landed system + descent system + entry system + delivery spacecraft attach systems

(The attach system frequently includes a spin up system.)

I'm not sure that the masses being discussed include the same elements.


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djellison
post Jun 15 2011, 03:42 PM
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The two are very clearly totally different spacecraft. One is a small airbag lander for a netlander style mission in the 150-200kg range that would last two years on the surface. The other is a Phoenix sized pulse-throttled-hydrazine engined EDL test soft lander in the 600kg range that will last one week on the surface.
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stevesliva
post Jun 15 2011, 06:44 PM
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QUOTE (djellison @ Jun 15 2011, 11:42 AM) *
The two are very clearly totally different spacecraft.


Yeah... certainly a head-scratcher. They're going to test the EDL system w/o airbags and then plan on using airbags? That validates pretty much only the E of EDL.
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rlorenz
post Jun 16 2011, 08:24 PM
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QUOTE (tolis @ Jun 14 2011, 03:32 PM) *
I think that the point behind the 2016 landing module is simply to demonstrate
an independent European capability to succesfully deliver instruments
to the Martian surface. To-date, only the US have had that
capability.


This raises a gnarly question. Define 'capability'. If I were pressed, I might call this
a demonstrated reliability to perform. Engineers like 99.5% ('3-sigma' - although a
translation of variance to probability in this way is predicated on Gaussianity, an
assumption that likely does not hold, but that's another thread, don't get me started
on exponentials and power laws....).

You cannot demonstrate 99.5% reliability without doing of order 200 trials. Agencies usually
wimp out after 1.

I'd submit that the US 'capability' may be statistically indistinguishable from good luck

While Beagle had its programmatic problems (and DS-2 for that matter), I don't believe
the loss of either mission is a robust experiment to show that those concepts would
not work (i.e. a lack of capability has not been demonstrated to any significance)
We only know that they failed (DS-2 might be considered 1.x failures - many
failure modes are common to both vehicles)


just my 1+(1/2)+(1/3)+(1/4)..... cents-worth
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Stuart H
post Aug 30 2011, 03:53 PM
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I'd submit that the US 'capability' may be statistically indistinguishable from good luck

While Beagle had its programmatic problems (and DS-2 for that matter), I don't believe
the loss of either mission is a robust experiment to show that those concepts would
not work (i.e. a lack of capability has not been demonstrated to any significance)
We only know that they failed (DS-2 might be considered 1.x failures - many
failure modes are common to both vehicles)


just my 1+(1/2)+(1/3)+(1/4)..... cents-worth
[/quote]

Guys,
Let's be totally honest here. The real purpose of the 2016 EDM is not 'technology demonstration' since, as Doug says above, it doesn't stack up.
No, it is political expediency. I speak as one who is working on the ExoMars mission.
In order for ESA/NASA to proceed with the overall ExoMars mission, which, let us be clear, is the only viable plan to support the return of surface/sub-surface samples from Mars to Earth (ie. MSR part 1), it needs the Italian financial contribution.
This means funding the 2016 EDM in order to allow the Italian share of the ExoMars work to be in line with its contribution.
This is the way that ESA works (it almost certainly is not the best way !)

No EDM, no ExoMars. (ie. No bucks, no Buck Rogers, as someone once said.)

Stuart Hurst,
Astrium UK.
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alphasam
post Aug 31 2011, 12:33 PM
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QUOTE (djellison @ Jun 14 2011, 11:03 PM) *
Mars-Next? Really?

It's mentioned on an ESA website from 3.5 years ago, and nowhere else.
http://www.esa.int/esaSC/SEMJA563R8F_index_0.html

That means it predates the 2016 EDL test being announced


Actually just to set things straight I'll think you'll find the EDL, or at least the original concept, easily predates the network mission. It's a drastically scaled-down version of Aurora's "2018: a technology precursor mission to demonstrate aerobraking/aerocapture, solar electric propulsion and soft landing (formerly envisaged as a smaller Arrow-class mission to be launched in 2010)" mentioned here back in 2003, that's why it looks like a strange bolt-on to 2016 TGO, because it is; I remember following the development (and downsizing) well. If I remember correctly it was orginally proposed as the first "Mars-NeXT" (Now part of MREP) back when the "-NeXT"s were conceived as tech demonstrators, ESA's planned Lunar Lander is the culmination of what was originally called "Moon-NeXT". I don't think it was planned as a direct test for the network mission specifically, and it appears that has gone with Beagle 2 heritage systems anyway, in fact since when does ESA ever conduct full-scale demonstrations of future missions or their technology? Each mission is it's demonstrator! I assume because of the decision to go with B2-like architecture in the network study it was decided to use the new Exomars-EDL to test a representative system for larger missions.

The Mars-Next mission is neither unfunded nor unfundable, in fact approval for the mission (whether it be the network or another of the studied missions) is being sought at next year's council of ministers. The fact is given the budget situation at NASA, the next MSR mission will almost certainly be delayed significantly so there will be plenty of room for an ESA-led mission in the meantime. Btw, from what i've seen it is only NASA that considers 2018 Exomars as the first part of MSR, ESA do not.
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Floyd
post Aug 31 2011, 01:49 PM
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QUOTE (rlorenz @ Jun 16 2011, 04:24 PM) *
just my 1+(1/2)+(1/3)+(1/4)..... cents-worth


If it is your 2 cents, then you probably want 1 + 1/2 + 1/4 +1/8--the harmonic series diverges


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djellison
post Aug 31 2011, 02:12 PM
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QUOTE (alphasam @ Aug 31 2011, 05:33 AM) *
in fact approval for the mission (whether it be the network or another of the studied missions) is being sought at next year's council of ministers.


So it's currently unfunded.

The EDL testbed is, as Stuart has very well explained, pork. Nothing more.
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alphasam
post Aug 31 2011, 03:29 PM
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Unfunded in the sense that it's as yet a proposal, just like MSR for that matter, preparatory work on the mission and others is funded through MREP. Given that it's going to the council next year it's clearly not unfundable, especially with future EU Space Programme funding, i'm not sure what makes you think it is.

I don't doubt there is a political element to the role of the current EDM but the fact is ESA's desire for an EDL demonstrator predates and was seperate to the joint ESA-NASA Exomars plan, it doesn't exist just because of political expediency. The EDL fits with stated desire of ESA to aquire precision soft landing experience as part of the Aurora roadmap, which it will suplement through the lunar lander.
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djellison
post Aug 31 2011, 03:39 PM
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You have your opinion, others may differ.

Spending hundreds of millions of euros and intentionally demanding a short surface mission is lunacy.
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alphasam
post Aug 31 2011, 04:04 PM
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This will be the case with the proposed lunar lander too. The point i'm making is this is not an issue of politicking concerning a single mission, but ESA's Human Spaceflight and Exploration programme as a whole which always has treated the science as of secondary importance.
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